This year's flu season is rivaling the worst in recent years, 53 flu-related deaths for the season

Sixteen flu-related deaths were reported Friday by the US Centers for Disease Control and Prevention in its weekly flu report.

According to the report, influenza activity is now widespread in 48 states and Puerto Rico, down from 49 states in the previous two weeks. Oregon joined Hawaii in lower activity levels for the week ending January 27.

This year's flu season is rivaling the worst in recent years, according to Dr. Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases.

Overall, the data showed 17,024 new laboratory-confirmed cases of illness during the week ending January 27, bringing the season total to 126,117. These numbers do not include all the people who have had the flu, as many do not see a doctor when sick.

Circulating virus strains included both B strains (Yamagata and Victoria), H1N1 and H3N2, according to the CDC. "It's an H3N2 year," Fauci said.

Historically, H3N2 strains have been "bad actors," he said, known to cause more complications, hospitalizations and deaths.

This virus strain is also a challenge to this year's flu vaccine.

Researchers in Canada reported in a recent study that the vaccine proved only 10% effective against the H3N2 virus, though the flu shot provided more protection against other currently circulating strains. (CNN_Feb-02)